Photomechanical method for producing cutting dies



Filed Sept. 26, 1963 Sept. 12, 1967 .T. H. BLAKE 3,341,329

PHOTOMECHANICAL METHOD FOR PRODUCING CUTTING DIES 2 Sheets-Sheet lINVENTOR. TREVOR H4 BLAKE ll... max/IQ;

Sept. 12, 1967 T. H. BLAKE 3,341,329 I PHOTOMECHANICAL METHOD FORPRODUCING CUTTING DIES Filed se t. 26, 1963 2 SheetsSheet 2 INVENTORTREVOR H. BLAKE United States Patent Jersey Filed Sept. 26, 1963, Ser.No. 311,788

8 Claims. (Cl. 96-36) This invention relates to a new and improvedmethod for the formation of cutting, scoring and/or embossing dies,which are of particular value in the formation of paperboard cartonblanks.

It has been found that the many costly and laborious hand operationsnecessary for producing conventional dies, which consist of a male diemember made up of metal knivesmounted in wooden furniture and a femaledie consisting of impressions cut in a paper member, can be eliminatedby the use of coacting, opposed dies formed from unitary metal plateshaving the working elements of the dies as an integral part thereofstanding in shallow relief above the background areas of the die plates.Such dies may be formed economically by removing portions of a thin,metal plate by chemical means to form the background or depressed areasof the plate, leaving the scoring and cutting edges standing above thebackground areas so formed. A further disadvantage of conventional diesis the fact that since the cutting knives must be made up from manysmall pieces, a great number of discontinuous cuts are produced. Thedies produced by my method, have the advantage that the cutting andscoring lines thereon maybe continuous.

It is of critical importance that the working edges or elements on theopposed die members be aligned precisely with respect to each other inorder that the desired cutting, scoring or embossing operations willoccur when the dies are used. One method for producing dies having thenecessary alignment involves the use of a complete drawing for each ofthe die plates to be produced. However the cost of preparing suchdrawings having the necessary precision renders this methoduneconomical. It is an object of the present invention to accomplish themanufacture of precisely aligned opposed die plates thru the use of onlya single drawing of the desired cutting, embossing and/or scoringpattern.

The principles of the present invention may be best understood from thefollowing specification and accompanying drawings, in which:

FIGURE 1 is a plan view of an example of the type of drawing used in thepreparation of aligned working elements on opposed die members,

FIGURE la is a magnified view of a portion of the drawing of FIGURE 1,

FIGURE 2 represents the optical transmission of a desired image from adrawing onto a photosensitive film or plate;

FIGURE 3 represents the optical transmission of a defrom a photographicfilm negative onto a metal plate having a photosensitive coating, and

FIGURE 4 is a cross-sectional view of a portion of a pair of opposedcoacting die plates in register, showing matched cutting and scoringworking areas thereon.

My new and improved method for making dies having precisely alignedworking areas involves the use of only a single drawing of a cartonblank or other desired cutting, creasing or embossing pattern. Thisdrawing will generally represent the composite working areas oneach ofthe opposed die plates, a desired portion of the composite drawing beingseparated out and imposed on a plate, the surface of which has beenphotosensitized by known procedures. Another portion of the compositeimage is separated out and imposed on a second plate to form amatchplied to metals, such modifications of which bears the imposed3,341,329 Patented Sept. 12, 1967 ing opposed die member image. Theplates subsequently are etched after removal of the photosensitiveresist from those areas of the respective plate not bearing images ofthe cutting and scoring elements.

The die plates may be made of any of a variety of etchable metals suchas magnesium, copper, steel, bronze and the like, the choice of theparticular metal to be utilized in a given case being determined by therelative importance of various factors such as durability, rapidity andease of etching, flexibility, economy and other factors. The etchingmedium used will depend on the particular metal which is to be etched,satisfactory etchants for each of the metals listed as well as otheretchable metals being well known in the art. In general, magnesium ismost often etched in a bath composition based primarily on nitric acidwhile copper, steel, and bronze are customarily etched with ferricchloride etchant compositions, although ammonium persulfate and otheroxidizing etchants may also be used. Similarly, the die plate may be ofa photopolymerizab'le plastic composition, such as photosensitized nylonor a photopolymerizable composition of a divinyl ester of a polyethyleneglycol or the like. The utilization of photopolymerizable plasticmaterials for the preparation of the die plates for my inventioninvolves certain modifications of the basic processes as apbeing obviousto those skilled in the art.

Referring first to FIGURE 1, a sheet of material 1, of a composition ofthe type described below, bears line drawing 2 of the composite workingareas of the opposed die members to be produced. On this drawing theworking surfaces of one of the die plates plus an amount sufficient toallow for undercutting of the resist coating by the etching solution areindicated by an indicating medium 3 (see also FIGURE 1a), while those ofthe opposed die member are indicated by a second indicating medium 4.Areas at which the working surfaces of the two die plates overlie eachother or overlap to form areas common to the plan images of both platesare indicated by yet another indicating medium 5. Theseindicating mediaare selected such that media 3 and 4 are separable from each other bytheuse of color filters or the use of sets of different colored lightsto illuminate sheet 1 at the time when images therefrom are imposed on acolorsensitive photographic surface, or by the use of photographic filmssensitized to some wave lengths, but insensitive to others. Indicatingmedium 5 is such that the optical-photographic techniques used toselectively separate out media 3 and 4 do not separate out medium 5.Thus two photographic negatives 6 may be formed, one image of the areasindicated "by media 3 and 5 (the image of medium 4 being eliminated bythe use of a particular optical-photographic technique), and the secondof which bears the imposed image of the areas indicated by media 4 and 5(the image of medium 3 being eliminated by an appropriateopticalphotographic technique), Creasing lines are indicated on FIGURES1 and 1a by the letter a, while cuttting lines are indicated by theletter 17.

In the preferred mode of carrying out the method, media 3 and 4 are ofcomplementary colors which easily can be separated from each other bythe use of color filters. These colors are indicated in FIGURE 1 asbeing red and blue. However, many other combinations of complementarycolors will immediately be obvious to those skilled in the art, such as.red and green, yellow and blue, and orange and purple. The media neednot be colors, but one of the media could instead be a composition whichfluoresces under given lighting conditions, whereas the other mediummight be a particular shade of gray, which could easily be separated bylighting techniques from the fluorescing composition.

Medium is shown in FIGURE 1 to be black. However, it should be obviousthat many other colors would also be suitable, particularly, in thisinstance, purple, which is a combination of the red and blue shown inFIG- URE 1. It will be understood from the following description that inmany cases the third medium will be unnecessary since no overlapping oftheworking surfaces on the line drawing 2 may be needed, for example, ifonly scoring is to be performed by the dies.

Drawing 1 may be prepared on any suitable material such as paper orplastic film. Since, however, a high degree of precision is necessary inthe dies produced, it is desirable that the material be one having highdimensional stability. One example of an appropriate material ispolyethylene terephthalate sheet. The lines of drawing 1 may be laiddown accurately with ink or may be carefully laid down with coloredtapes of a preselected width and color. As seen in FIGURE 2 the image ofthe desired portion of line drawing 2 is imposed upon photosensitivefilm or plate 6. The exposure is readily accomplished by the use ofcamera 7. It will be apparent that in order to increase the accuracy ofthe positioning of the working surfaces 7 on the die plates to beproduced, line drawing 2 should be made on an enlarged scale and thenreduced photographically. Then, for example, if the accuracy attainablein the drafting method is 10.005 inch, and the size of the image isreduced by a factor of 5, the maximum error in the photographicallyimposed image will be only 10.001 inch.

In the preferred embodiment of my invention, two photographic negatives,each of which bears the image of the working surfaces of one of the dieplates, as described above, are produced on films 6. As shown in FIGURE3, each negative 6 is then placed in direct contact with the surface ofa metal plate 8 coated with a photosensitive resist 9. Coating 9 is thenexposed to light from a light source 10 passing through the negative 6.Since the negative is transparent only at the portions corresponding toimage 2, this same image is imposed on coating 9. The exposed metalsheets or plates are then developed and fixed in conventional manner andthe resulting sheets, bearing a protective resist coating only in thoseareas corresponding to the cutting and scoring elements, are etched in asuitable etchant bath to a depth ranging from 0.005 to 0.035 inch,depending on the stock to be cut and creased. The finished opposedcoacting die plates consisting of thin flexible metallic plates willthen bear the cutting and scoring elements in shallow relief.

If the basic material constituting the die plate is a photopolymerizedplastic such as nylon or a polyethylene glycol divinyl estercomposition, for example, the image of the cutting and scoring elementsis transfersed through the medium of the suitable negatives directlyonto the surface of the photosensitive plastic sheet, which is thendeveloped and hardened by conventional processes for treating theparticular photopolymerizable plastic material utilized. As representedin FIGURE 4, which shows cooperating sections of finished die plates inregister, the plate 20 bears paired female scoring elements 22a and 22bin register with male scoring element 23 of plate 21. Also shown arecutting elements 24 and 25 on plates 20 and 21 respectively.

The height h of the male scoring element, the width w of the malescoring element, the width k of the groove in the female scoring elementand the depth d of the female groove are all factors which influence thequality of the score which is formed in a paperboard sheet impressedbetween the dies. Also these factors are related to the particular typeand caliper of the paperboard being processed. To obtain satisfactoryscore lines in paperboard, the height h (FIGURE 4) should range fromabout 0.005 inch to 0.035 inch above the die plate background, dependingon the caliper of the paperboard being processed, and preferably theheight h should be between 0.5 and 2 times the paperboard stockthickness. The optimum height h of the male scoring element isapproximately 0.8 times the thickness of the paperboard stock. Forexample, the optimum height h of the male scoring element, for scoringpaperboard of 0.010 inch thickness, was found to be 0.008 inch, for0.017 inch thick paperboard about 0.015 inch and for 0.026 inch thickpaperboard about 0.022 inch.

The width w of the male scoring element 23 may range from about 0.5 to2.0 times the paperboard thickness, the optimum being about 0.8 to 1.2times the paperboard thickness. Satisfactory results have been obtainedwhen the width k of the groove between the paired raised por.

tions 22a and 22b of the female scoring element ranges from about 2.0 toabout 4.0 times the thickness of the paperboard being processed, 2.5 to3.5 times such thickness being optimum. This groove width k preferablyequals the width w plus 1.5 to 2.5 times the paper stock thickness. Thedepth d of the groove between the raised portions 22a and 225 maysuitably range between about 0.5 and 1.5 times the paperboard stockthickness or even slightly deeper, although greater depth presents nosubstantial advantage. The depth d preferably should be at leastsubstantially equal to the height h.

The amount of vertical gap v between the plates (that is, the closestvertical distance between the working elements of the plate when thepress is on impression) substantially affects the operation of thecutting elements. A further factor, closely related, is the amount ofhorizontal overlap g of the co -acting cutting elements 24 and 25, oneof which is integral with each of the opposed die members. Optimumcutting conditions obtain if the cutting members overlap to a smalldegree, which should not normally exceed about 50% of the paperboardstock thickness. If there is too much overlap the paperboard stock maymerely be compressed, and not cut. Satisfactory cut lines may also beobtained if the cutting members do not overlap but rather have a gaptherebetween of not more than about 20% of the paperboard stockthickness. The gap v between the cutting elements when the press is onimpression may be up to about 50% of the thickness of the paperboardstock being cut. The preferred combination of horizontal and verticalrelationships between cutting members for producing cleanly cutpaperboard of a variety of thicknesses combines a vertical gap v of0.003 to 0.005 inch with a horizontal overlap g of 0.002 to 0.004 inch.That is, when the press is on impression, the vertical distance vbetween the cutting members of the die is between 0.003 and 0.005 inch,and the overlap g of the cutting members is 0.002 and 0.004 inch, eachcutting element overlapping the actual desired line of cut by 0.001 to0.002 inch.

My invention is further illustrated by the following examples which aregiven for purposes of illustration only, the invention not being limitedthereto. 1

Example I Steel dies are prepared for use in cutting out and scoringpaperboard carton blanks. Creasing elements are provided on the opposeddie plates to cooperate to crease the sheet material where it is to befolded and cutting elements are provided to cut an outline of the cartonblank and provide the carton blank with the desired slits and notches.The carton blank is drawn on a sheet of polyethylene terephthalate, on ascale of five times the desired final size of the carton. The basiclayout and the line width layout are made with pencil. Black ink then isapplied at the portions where the working elements will overlap oneanother, allowance also being made for undercutting of the resistcoating by the etching solution. It is known that for etching steel, andetching solution containing 20% nitric acid will undercut the coatingapproximately 0.010 inch per edge for an etching depth of 0.015 inch.Each of the cutting elements is toextend 0.001 inch beyond the cuttingline, i.e., the cutting elements will overlap a distance of 0.002 inch,and the final width of the working surfaces is to be 0.030 inch. Theoverlapping areas of the working surfaces are to be represented inblack. The width of the black lines 5 (FIG- URE 1a) will then be 0.002inch overlap plus 0.020 inch to allow for the anticipated undercut for atotal width of 0.022 inch. The black area will, then, overlie the linesof the pencilled drawing which are to be the cut lines in the finishedcarton blank, and will extend an equal distance (0.011 in.) on each sideof the pencilled center line. The working surfaces of the cuttingelements of one of the dies exclusive of the overlap area are indicatedby red ink while the corresponding portions of the working surfaces ofthe cutting elements on the other die are indicated by a complementarycolor, blue. The distance from the center line to the edge of theworking surface is 0.029 inch (0.030 inch less 0.001 inch overlap). Tothis dimension is added 0.010 inch to allow for undercut at the outsideedge, making a total distance of 0.039 inch from the center line to theedge of the red or blue lines. Scoring surfaces having a width of 0.020inch are formed by the use of a blue line 0.040 inch wide centered overthe score line. A red line 0.040 inch wide is placed on each side of theblue line. Sufiicient clearance between the coacting elements isprovided by the undercutting effect of the etching solution. All of theabove dimensions are multiplied by a sizing factor of five and thedrawing is inked in using the appropriate colors. The drawing isilluminated by conventional tungsten lamps. A camera is then set forsize reduction by a factor of five and two exposures are made onseparate photographic plates, the first with a red filter and the secondwith a blue filter. Two photographic negatives. are produced from thetwo exposures. One will contain the photographic representations of theblue and black areas, the other will record the red and black areas.Each negative after being developed in accordance with conventionalprocedures is then placed in contact with the surface of a steel platecoated with photosensitive resist composition. The coated steel platesare then exposed to light through the photographic negatives to imposeimages of the line widths, including the allowances for undercutting,onto the resist composition which becomes insoluble to the etchingsolution at the areas where it has been so exposed. After washing awaythe unexposed resist coating with water, the exposed resist portions arebaked to increase their resistance to the etching solution and the steelplates are etched to a depth of 0.015 in. by treatment with 20% nitricacid solution for approximately 15 minutes.

Example 11 'Die plates are constructed from thin sheets of magnesium.Since the amount of undercutting in using the etching solution mentionedbelow on magnesium is negligible; no allowance for undercutting need beadded to the line widths on the line drawing of the carton blank. Thesteps are carried out as in Example I above, and the magnesium platesare etched to a depth of 0.015 inch, using an etching solutioncontaining 11% nitric acid, 7% diethylbenzene, 0.4 dioctyl sodiumsulfosuccinate and 0.0001% gelatin, the latter additives being used toeliminate undercutting of the resist coating by the acids.

Example 111 The procedure of Example I is repeated except that the useof color filters is eliminated, and separation of the indicating mediais instead achieved by making a first exposure-on a photosensitive platewhich is sensitive only to the red and black colored portions of thedrawing and a second exposure on a photosensitive plate which issensitive only to the blue and black colored portions of the drawing.

The die plates of the present invention are effective in the cutting andscoring both of uncoated paperboard and paperboard coated with a varietyof protective and decorative coatings, including lacquers, varnishes,polymeric materials, such as the polyolefins and various polymerizedvinyl compounds and the like. The combined cutting and scoring dieplates. produced by my method may be of varying thickness, depending onthe particular type of press on which they are to be used and thecaliper and character of the paper stock that is to be cut and scored.The minimum practical thickness of the die plates is about 0.005 inchgreater than the height of the scoring and cutting elements above theetched background. Thus, for use in cutting and creasing of 0.010"paperboard, the overall die plate thickness may be as little as about0.013 inch. For cutting and scoring of 0.017" paperboard, the overalldie plate thickness may range upward from about 0.020 inch, and platethicknesses of about 0.026 inch are satisfactory for preparation of diesfor cutting and scoring of 0.026 inch thick paperboard, assuming in eachcase an etched depth of about 0.8 times the thickness of the paperboardbeing processed. Similar relationships exist for paperboard of otherthicknesses. The dies produced by my method have been found tosuccessfully cut sheet metal of thin gauge as well as paperboard.

It will be noted that the cutting and scoring dies may very much thinnerand consequently more flexible than conventional cutting and scoringdies made from an assembly of individual rules and furniture block,maximum plate thickness of 0.04 inch being ample to provide cutting andscoring elements of optimum dimensions for all normal operations on evenvery heavy paperboard stock. In general, it is desirable from thestandpoint of economy and utility to use die plates of near minimumthickness. The very thin plates of the invention are sufficiently lightin weight to be adhesively secured to either fiat or cylindrical pressmembers without the necessity of clamps or screws. A preferred operationis to clamp each of the die plates to the outer surface of a cylindricalpress member.

It is often desirable also to provide holes through the plates foraccurately registering the plates on the press members. This canconveniently be done by indicating the location of the holes on thedrawing with an indicating means which will be imposed upon each of thephotographic negative produced. The holes may then be accurately drilledat the same point on each of the plates, using thephotographically-imposed marks on the plates for locating the positionsthereof.

If desired, die elements may be etched directly on the surfaces of apair of metal cylinders of the same diameter instead of on thinfiexi'bleplates.

My method can be used to produce dies which will form reverse scorelines, i.e., dies which have male scoring elements on each of the dieplates in registry with corresponding female elements on the other dieplate. This result is unfeasible with conventional dies on which one ofthe die members contains all of'the working elements and thecorresponding female elements are in the form of indentations on a sheetof backing paper or a grooved metal plate except by passing the sheetmaterial through two successive different dies the first of whichpresses on one surface and the second presses on the other. Scoringelements for producing reverse scores can be produced by my methodsimply by indicating the respective male scoring elements in the form oflines centered on the desired score lines, some of such lines being laiddown in one and some in the other of a selected pair of mutuallyseparable indicating'media. On each side of these lines is then placed aline in the other medium. The image imposed on each of the die plateswill then include some male and some female elements.

It is obvious from the foregoing description that the method of thisinvention will result in the production of cooperating die elements, theworking surfaces of which are very precisely aligned with respect toeach other. Since the working surfaces on each of the opposed membersare produced from the same drawing, any errors which occur in thedrafting of the carton blank will show up to the same extent in theworking surfaces of each of the cooperating die plates and thus will notaffect the registry of the plates with respect to each other.

Various other modifications of the die forming process herein describedwill suggest themselves to those skilled in the art, and it is notintended, therefore, that the scope of the invention be limited exceptas specifically set forth in the appended claims.

I claim:

1. In a method for producing a cutting and scoring die for working asheet material along a preselected pattern of cut lines and score lines,said die comprising a pair of opposed, coacting die members, each memberbeing all of one homogeneous piece and including as working elements onits working surface in shallow relief one of a coacting pair of cuttingelements and one of a pair of coacting scoring elements, said pairedcutting elements having their longitudinal axes slightly displaced onopposite sides of a desired cut line to be formed in said sheet materialand said scoring elements including a male scoring element thelongitudinal axis of which is centered on a desired score line to beformed in said sheet material and a female scoring element comprisingtwo raised areas parallel to and having their longitudinal axes slightlyand equally displaced on opposite sides of said desired score line,which method comprises the steps of forming a plan image of each of saidcutting and scoring elements, optically transferring the plan image of afirst member of each of said pairs of elements onto a firstphotosensitive surface and the plan image of the second member of eachof said pairs of elements onto a second photosensitive surface, removingby chemical means material from said surfaces except in the regionsbearing said images to produce a pair of matched opposed coactingcutting and scoring dies having said cutting and scoring elements asintegral portions thereof in shallow relief above the background areasof said surfaces, the improvement which comprises:

forming a single drawing including the plan images of both members ofeach pair of working elements, the plan image of the working elements ofthe first of said pair of die members being marked on said drawing inthe combination of a first indicating medium and a second indicatingmedium, the plan image of the working elements of the other of said pairof die members being marked on said drawing in the combination of thesecond indicating medium and a third indicating medium, the secondindicating medium comprising an area common to the plan images ofcertain working elements of both die members, said common area beingaligned with and substantially equivalent in length to a line of workingin said sheet material to be worked and having a critical widthprecisely related to the displacement of the longitudinal axes of theworking elements from the desired line of working and to the degree ofundercutting resulting from chemical removal of material in forming saiddie,

said first and third indicating media being optically separable fromeach other and said second indicating medium being optically combinablewith either of said first and third indicating media under conditionswhich exclude the other of said first and third media.

2. The method of claim 1 wherein said first and third indicating mediaare complementary colors and said exclusion is effected by passing saidoptical transmissions through color filters.

3. The method of claim 2 wherein said complementary colors are red andblue.

4. The method of claim 3 wherein said second indicating medium is black.

5. The method according to claim 1, including the steps of:

(a) optically transmitting the image of said first and second indicatingmedia onto a photosensitive plate While substantially excluding theimage of said third medium,

(b) optically transmitting the image of said second and third indicatingmedia onto a second photosensitive plate while substantially excludingthe image of said first medium,

(c) removing by chemical means material from said plates except in theregions bearing said imposed images to produce a pair of matchedcoacting die plates having the working surfaces as integral partsthereof in shallow relief above the plate background areas of saidplates.

6. The method according to claim 1, including the steps of:

(a) optically transmitting the image of said first and second indicatingmedia onto a photosensitive film while substantially excluding the imageof said third indicating medium,

(b) developing said first film to produce a first photographic negative,

(c) optically transmitting the images of said second and thirdindicating media onto a second photosensitive film while substantiallyexcluding the image of said first medium,

((1) developing said second photographic negative,

(e) exposing a first photosensitive metal plate to light through saidfirst negative to impose an image on said plate,

(f) exposing a second photosensitive metal plate to light through saidsecond negative to impose an image on said plate, 7

(g) removing by chemical means material from said plates except in theregions bearing said imposed images to produce a pair of matchedcoacting die plates having the working surfaces as integral partsthereof in shallow relief above the plate background areas of saidplates.

7. The method of claim 1 wherein the surfaces marked with said firstmedium described both male scoring elements and female scoring elementsat desired positions, and the surfaces marked with said third mediumdescribe corresponding female and male scoring elements whereby one ofthe die plates produced will have both male and female scoring elementsthereon and the coacting die plate will have the corresponding coactingfemale and male scoring elements thereon.

8. In a method for producing a die for forming a line of severance in asheet material, said die comprising a pair of opposed, coacting diemembers, each member being all of one homogeneous piece and including onits working surface in shallow relief one of a coacting pair of cuttingelements, said cutting elements having their longitudinal axes slightlydisplaced on opposite sides of the desired line of severance to beformed in the sheet material, which method comprises the steps offorming a plan image of each of said cutting elements, opticallytransferring the plan image of the first of said elements onto a firstphotosensitive surface and the plan image of the second of said elementsonto a second photosensitive surface, removing by chemical meansmaterial from said surfaces except in the regions bearing said images toproduce a pair of matched opposed coacting cutting dies having saidcutting elements as integral portions thereof in shallow relief abovethe background areas of said surfaces, the improvement which comprises:

forming a single drawing including the plan images of both of saidcutting elements, said drawing having an area common to the plan imagesof both cutting elements, said common area being centered on andsubstantially coincident in length to the desired line of severance tobe formed in the sheet material and having a critical width preciselyrelated to the displacement of the longitudinal axes of the cuttingelefilm to produce a second ments from the desired line of severance andto the degree of undercutting resulting from said chemical removal ofmaterial in forming said dies, said plan image of said first cuttingelement being marked on said drawing in the combination of a firstindicating medium and a second indicating medium, said plan image ofsaid second cutting element being marked on said drawing in thecombination of the second indicating medium and a third indicatingmedium, the second indicating medium comprising said common area in saiddrawing, said first and third indicating media being optically separablefrom each other and said second indicating medium being opticallycombinable with either of said first and third indicating media underconditions which exclude the other of said first and third media.

References Cited 5 UNITED STATES PATENTS NORMAN G. TORCHIN, PrimaryExaminer. J. TRAVIS BROWN, Examiner. 15 R. H. SMITH, Assistant Examiner.

1. IN A METHOD FOR PRODUCING A CUTTING AND SCORING DIE FOR WORKING ASHEET MATERIAL ALONG A PRESELECTED PATTERN OF CUT LINES AND SCORE LINES,SAID DIE COMPRISING A PAIR OF OPPOSED, COACTING DIE MEMBERS, EACH MEMBERBEING ALL OF ONE HOMOGENEOUS PIECE AND INCLUDING AS WORKING ELEMENTS ONITS WORKING SURFACE IN SHALLOW RELIEF ONE OF A COACTING PAIR OF CUTTINGELEMENTS AND ONE OF A PAIR OF COACTING SCORING ELEMENTS, SAID PAIREDCUTTING ELEMENTS HAVING THEIR LONGITUDINAL AXES SLIGHTLY DISPLACE ONOPPOSITE SIDES OF A DESIRED CUT LINE TO BE FORMED IN SAID SHEET MATERIALAND SAID SCORING ELEMENTS INCLUDING A MALE SCORING ELEMENT THELONGITUDINAL AXIS OF WHICH IS CENTERED ON A DESIRED SCORE LINE TO BEFORMED IN SAID SHEET MATERIAL AND A FEMALE SCORING ELEMENT COMPRISINGTWO RAISED AREAS PARALLEL TO AND HAVING THEIR LONGITUDINAL AXES SLIGHTLYAND EQUALLY DISPLACED ON OPPOSITE SIDES OF SAID DESIRED SCORE LINE,WHICH METHOD COPRISES THE STEPS OF FORMING A PLAN IMAGE OF EACH OF SAIDCUTTING AND SCORING ELEMENTS, OPTICALLY TRANSSFERRING THE PLAN IMAGE OFA FIRST MEMBER OF EACH OF SAID PARIS OF ELEMENTS ONTO A FIRSTPHOTOSENSITIVE SURFACE AND THE PLAN IMAGE OF THE SECOND MEMBER OF EACHOF SAID PAIRS OFELEMENTS ONO A SECOND POHOTSENSITIVE SURFACE, REMOVINGBY CHEMICAL MEANS MATERIAL FROM SAID SURFACES EXCEPT IN THE REGIONSBEARING SAID IMAGES TO PRODUCE A PAIR OF MATCHED OPPOSED COACTINGCUTTING AND SCORING DIES HAVING SAID CUTTING AND SCORING ELEMENTS ASINTEGRAL PORTIONS THEREOF IN SHALLOW RELIEF ABOVE THE BACKGROUND AREASOF SAID SURFACES, THE IMPROVEMENT WHICH COMPRISES: FORMING A SINGLEDRAWING INCLUDING THE PALN IMAGES OF BOTH MEMBERS OF EACH PAIR OFWORKING ELEMENTS OF THE FIRST OF PLAN IMAGE F THE WORKING ELEMENTS OFTHE FIRST OF SAID PAIR OF DIE MEMBERS BEING MARKED ON SAID DRAWING INTHE COMBINATION OF A FIRST INDICATING MEDIUM AND A SECOND INDICATINGMEDIUM, THE PLAN IMAGE OF THE WORKING ELEMENTS OF THE OTHER OF SAID PAIROF DIE MEMBERS BEING MARKED ON SAID DRAWING IN THE COMBINATION OF THESECOND INDICATING MEDIUM AND A THIRD INDICATING MEDIUM, THE SECONDINDICATING MEDIUM COMPRISING AN AREA COMMON TO THE PLAN IMAGES OFCERTAIN WORKING ELEMENTS OF BOTH DIE MEMBERS, SAID COMMON AREA BEINGALIGNED WITH AND SUBSTANTIALLY EQUIVALENT IN LENGTH TO A LINE OF WORKINGIN SAID SHEET MATERIAL TO BE WORKED AND HAVING A CRITICAL WIDTHPRECISELY RELATED TO THE DISPLACEMENT OF THE LONGITUDINAL AXES OF THEWORKING ELEMENTS FROM THE DESIRED LINE OF WORKING AND TO THE DEGREE OFUNDERCUTTING RESULTING FROM CHEMICAL REMOVL OF MATERIAL IN FORMING SAIDDIE, SAID FIRST AND THIRD INDICATING MEDIA BEING OPTICALLY SEPARABLEFROM EACH OTHER AND SAID SECOND INDICATING MEDIUM BEING OPTICALYCOMBINABLE WITH EITHER OF SAID FIRST AND THIRD INDICATING MEDIA UNDERCONDITIONS WHICH EXCLUDE THE OTHER OF SAID FIRST AND THIRD MEDIA.